Single stick operation of a work tool

ABSTRACT

An excavation machine includes a chassis, a tool movably coupled to the chassis, an input device, and a controller operative to control movement of the tool to move earth at the job site. The controller may control movement of the tool along a predetermined path based on a tool motion sequence programmed at the controller. The controller may control a velocity of the tool along the predetermined path based on a position of the input device.

FIELD OF THE INVENTION

The present disclosure relates to a work vehicle having an operator input device for adjusting a rate of a work tool during automated movement of the work tool along a predetermined path.

BACKGROUND OF THE INVENTION

Excavation machines are operative to move soil, sand, gravel, rock, or other suitable material at a jobsite. Excavation machines, which may include backhoes, excavators, and other earth moving machines, require a certain amount of skill to operate. Typically, each hydraulic function on an arm of the excavation machine is operated independently by actuation of motions of joysticks. The joysticks may be directly mechanically coupled to hydraulic valves via linkages to control the valves and therefore the hydraulic functions of the excavation arm. The joysticks may incorporate pilot hydraulic valves coupled to larger hydraulic valves via a pilot circuit. Alternatively, the joysticks may be coupled to the hydraulic valves electronically through an electro-hydraulic circuit. In each configuration, one motion of the joystick typically directs one hydraulic function.

The single hydraulic function per joystick motion arrangement places the responsibility for coordination of multiple axes onto the operator and raises the requirements for operator skill and experience. Skilled operators are often short in supply and costly depending on the local market.

Several operations performed by excavation machines, such as trenching and hole boring, for example, involve repetitive and cumulative motion and may be described in advance of operation. Accordingly, automated motion control techniques have been developed for excavation machines that employ a time versus displacement algorithm to move the articulated arm through space with a pre-programmed velocity and trajectory. However, these automated motion techniques may not be suitable for digging conditions that require variable velocity and/or variable force of the tool, such as in sandy, clayey, and rocky soils of construction sites.

SUMMARY

According to an embodiment of the present disclosure, a work vehicle for moving earth at a job site is provided. The work vehicle includes a chassis, a ground engaging mechanism configured to support the chassis, and a tool movably coupled to the chassis and configured to move earth at the job site. The work vehicle further includes a controller operative to control movement of the tool based on a tool motion sequence programmed at the controller to move the tool along a predetermined path. The work vehicle further includes an input device that is movable by an operator and is operatively coupled to the controller. The controller is operative to control a velocity of the tool along the predetermined path based on a position of the input device.

According to another embodiment of the present disclosure, a method is provided for moving earth at a job site with a work vehicle. The method includes controlling, by tool motion control logic of a controller of the work vehicle, movement of a tool of the work vehicle based on a tool motion sequence programmed at the controller to move the tool along a predetermined path. The method includes detecting an actuation of an operator input device. The operator input device is operatively coupled to the controller. The method further includes adjusting a velocity of the tool during the movement of the tool based on the detected actuation of the operator input device.

According to yet another embodiment of the present disclosure, a work vehicle is provided for moving earth at a job site. The work vehicle includes a chassis, a ground engaging mechanism configured to support the chassis, and a tool movably coupled to the chassis and configured to move earth at the job site. The work vehicle includes a controller programmed to move the tool from a first position to a second position along a predetermined path. The work vehicle further includes an operator input device in communication with the controller to adjust a rate at which the tool moves from the first position to the second position.

In one example, the controller controls the rate at which the tool moves from the first position to the second position to be proportional to a degree of actuation of the operator input device. In another example, the controller is operative to calculate the predetermined path based on at least one received input identifying at least one of a geometric dimension and a geographical location of a desired topographical feature to be formed at the job site. In this example, the controller is operative to move the tool along the predetermined path to form the desired topographical feature at the job site. In another example, a tool motion sequence programmed at the controller identifies the predetermined path, and the tool motion sequence identifies a stroke trajectory of the tool for each of a plurality of strokes of the tool through the earth to identify the predetermined path. In another example, the controller is programmed to initiate movement of the tool from the first position to the second position upon detection by the controller of a movement of the operator input device.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of an exemplary excavation machine having an excavation tool;

FIG. 2 is a block diagram an exemplary control system of the excavation machine of FIG. 1 for controlling the excavation tool;

FIG. 3 is a schematic view of a display of the present disclosure shown in a side view mode;

FIG. 4 is an exemplary joystick device for adjusting the velocity of the excavation tool of FIG. 1; and

FIG. 5 is a flow diagram of an exemplary method of controlling the excavation tool during an automated motion sequence of the excavation tool.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. While the embodiments described herein relate to the control of an excavation tool of an excavation machine, the method and systems may also be used with other suitable vehicles and other suitable work tools, such as, for example, blades, augers, forks, bail lifts, harvesters, tillers, grapples, etc.

The term “logic” or “control logic” as used herein may include software and/or firmware executing on one or more programmable processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), hardwired logic, or combinations thereof. Therefore, in accordance with the embodiments, various logic may be implemented in any appropriate fashion and would remain in accordance with the embodiments herein disclosed.

With reference to FIG. 1, the present disclosure relates to an excavation machine 10 configured to perform multiple operations to move soil or other suitable materials at a jobsite. Although excavation machine 10 is illustratively shown as a tracked excavator 10, excavation machine 10 may be any suitable vehicle operative to move earth at a jobsite, such as a wheel-based excavator, a tractor-based backhoe (e.g., see machine 10 of FIG. 3), and other suitable machines. As illustrated in FIG. 1, excavation machine 10 includes a chassis 12, an operator cab 14 supported by chassis 12, and an excavation tool 18 movably coupled to chassis 12. Chassis 12 is supported by one or more ground engaging mechanisms 16, illustratively tracks, operably coupled to an engine or motor (e.g., engine 48 of FIG. 2) for propelling excavation machine 10.

Ground engaging mechanisms 16 may alternatively include wheels or other suitable devices for supporting excavation machine 10 on the ground.

Excavation tool 18 illustratively includes a bucket 20 operative to dig, move, and hold material, although another suitable implement 20 configured to move earth at the job site may be provided. Excavation tool 18 further includes a first, boom arm 22 and a second, dipper arm 24 that are movable with hydraulic actuators, illustratively hydraulic cylinders 26, 28. Excavation machine 10 is operative to perform an excavation, such as digging a trench or hole and/or otherwise moving material, through the coordinated movement of boom arm 22, dipper arm 24, and bucket 20. Boom arm 22 is movably coupled to chassis 12 at pivot pin 36 a, and dipper arm 24 is movably coupled to boom arm 22 at pivot pin 36 b. Boom arm 22 is raised and lowered relative to chassis 12 with one or more hydraulic cylinders 26, and dipper arm 24 is raised and lowered relative to boom arm 22 with one or more hydraulic cylinders 28. Bucket 20 is coupled to dipper arm 24 at pivot pin 36 c and is moved relative to dipper arm 24 with one or more hydraulic cylinders 30. Hydraulic cylinders 26, 28, 30 are positioned and oriented such that they perform work either through expansion or retraction.

Referring to FIG. 2, excavation machine 10 includes an on-board controller 50 for controlling operation of excavation tool 18 of excavation machine 10. In one embodiment, controller 50 includes an appropriately programmed general-purpose computer, such as a laptop model, for example. It is also within the scope of the present disclosure that controller 50 may be located off-board or apart from excavation machine 10. Controller 50 includes one or more processors 52 and a memory 54 accessible by the processor(s) 52. Memory 54, which may include non-volatile memory, includes one or more physical memory locations and may be located internal or external to controller 50. Processor 52 illustratively includes tool control logic 56 that is operative to control the trajectory and velocity of excavation tool 18 for performing excavations and otherwise moving material with excavation tool 18. Controller 50 may be used to control other devices and systems of excavation machine 10.

Tool control logic 56 of controller 50 illustratively controls a hydraulic circuit 60 for manipulating excavation tool 18. Hydraulic circuit 60 includes hydraulic cylinders 26, 28, 30 of FIG. 1. Hydraulic circuit 60 also includes, for example, a hydraulic pump driven by engine 48 for supplying hydraulic fluid to cylinders 26, 28, 30 and hydraulic control valves for regulating the delivery of the hydraulic fluid to cylinders 26, 28, 30. Controller 50 provides electrical control signals to the hydraulic control valves to control the actuation of the hydraulic cylinders 26, 28, 30 and therefore the movement of excavation tool 18.

Tool control logic 56 of controller 50 controls excavation tool 18 based on inputs from a plurality of input devices (e.g., devices 64, joystick 34) and/or one or more code modules stored in memory 54. In the illustrated embodiment, tool control logic 56 is operative to execute a tool motion sequence programmed at controller 50 to automatically move excavation tool 18 along a predetermined path to perform an excavation. The tool motion sequence includes a time versus displacement algorithm, for example, for moving the articulated tool 18 through space with a pre-programmed trajectory. For example, the tool motion sequence, calculated in advance of operation, identifies a trajectory and orientation of bucket 20 for a series of passes or strokes of bucket 20 through the earth for performing an excavation. As such, tool control logic 56 is operative to provide automated control of tool 18 to perform the excavation based on the tool motion sequence. A user may initiate the automated tool motion sequence via a user input device 64, such as a lever or button, for example, or via a joystick 34. Tool control logic 56 may execute the tool motion sequence for controlling other operations and other suitable work tools, such as, for example, blades, augers, forks, bail lifts, harvesters, tillers, grapples, etc.

The tool motion sequence is provided in a tool motion code module 58, such as software or firmware code, stored at memory 54 and executed by tool control logic 56. In particular, tool motion code module 58 includes data describing the tool motion sequence of the excavation tool 18. As such, when executed by processor 52, tool motion code module 58 causes controller 50 to control movement of excavation tool 18 based on the tool motion sequence identified with the code module 58. In one exemplary embodiment, controller 50 calculates and stores the tool motion sequence of code module 58 based on user inputs specifying parameters that describe the desired operation (e.g., excavation) and based on position feedback for tool 18 and machine 10 provided with a positioning system. As such, the tool motion sequence of code module 58 is calculated and modified by controller 50 based on the user inputs and the positioning feedback. Exemplary parameters include the geometric dimensions as well as geographical location of a desired topographical feature (e.g., trench, hole, other excavation, etc.) to be formed at the job site. The desired geometric dimensions include, for example, a width, length, depth or height, volume, a slope of a bottom surface, side surface angles, or any other suitable dimensional data describing the desired topographical feature. Further, the user specifies the desired geographical location of the topographical feature, such as the location of the desired topological feature relative to machine 10 or relative to one or more location markers at the job site.

In one embodiment, at least some of the geometric and geographical parameters are entered numerically by the operator via input devices 64. In one embodiment, controller 50 receives the user inputs specifying the excavation parameters from a touch screen or keyboard/mouse. Other suitable input devices 64 (e.g., USB device, wireless device, etc.) may be used by a user for specifying the desired excavation parameters. In one embodiment, at least some of the parameters are identified by manipulating tool tip 21 to identify the extents of the desired geographical feature at the job site, as described below. In another embodiment, at least some of the excavation parameters of the tool motion sequence are predetermined and are not based on operator input, and code module 58 is generated on a computing system separate or remote from controller 50 prior to execution by controller 50. In this embodiment, the pre-generated code module 58 is loaded onto memory 54 of controller 50 for execution.

Controller 50 calculates and/or executes the tool motion sequence of code module 58 further based on position feedback from a positioning system. As illustrated in FIG. 2, the positioning system of excavation machine 10 includes tool position sensors 66 and one or more global positioning system (GPS) devices 68 for detecting the position and orientation, as well as geographical location, of excavation tool 18 and machine 10. In particular, position sensors 66 are provided on excavation tool 18 to provide tool position and orientation feedback signals to controller 50. Exemplary tool position sensors 66 include rotary pin encoders mounted at pivot pins 36 (see 36 a, 36 b, 36 c of FIG. 1) that are operative to detect the relative rotational positions of arms 22, 24 and bucket 20 on pivot pins 36. Other exemplary tool position sensors 66 include linear encoders mounted at hydraulic cylinders 26, 28, 30 that are operative to detect the extension of cylinders 26, 28, 30. In addition, excavation machine 10 includes one or more GPS device(s) 68 for detecting the geographical location of excavation machine 10 and excavation tool 18. Controller 50 determines the geographical location and orientation of the excavation machine 10 on the earth, as well as the area of the job site where the desired topographical feature is to be formed, based on the location of the GPS antenna(s) (e.g., GPS antenna 38 of FIG. 1) mounted to machine 10 and/or at the job site (e.g., using triangulation techniques). Additional GPS antennas and devices may be provided on excavation machine 10 and at the job site as needed.

In one embodiment, the location of the tool tip (e.g., bucket tooth tip 21 of bucket 20) is used to identify and record the locations of the extents of a desired excavation or other topographical feature. For example, with machine 10 positioned near the location where the desired topographical feature is to be formed, tool 18 is manipulated by an operator such that the bucket tip 21 is positioned at various locations along the boundary or perimeter of the desired excavation location. At each boundary location, the position of tool tip 21 is recorded based on the GPS location information provided with one or more GPS antennas mounted on tool 18. A GPS antenna may be mounted at tool tip 21. Alternatively, the location of the tool tip 21 may be calculated based on the arm angles and offsets between the tool tip 21 and antenna(s) mounted on work tool 18. In one embodiment, an operator uses an input device 64 (e.g., joystick button, GUI button, etc.) to signal to the controller 50 to record the current location of the tool tip 21 when identifying the excavation boundaries. In one embodiment, upon defining the extents of the desired excavation, other geometric dimensions, such as the depth, bottom slope, contours, and other characteristics of the desired excavation, are specified by the user with input devices 64, as described above. In one embodiment, these other geometric dimensions of the desired excavation are identified by specifying corresponding offsets from the defined boundary locations.

In another embodiment, controller 50 obtains the trajectory of tool 18 for the tool motion sequence by recording the motion of tool 18 as the tool 18 is moved by the operator. For example, the trajectory of tool 18 may be stored for one or more passes of the tool through the earth, such as when an operator manually controls tool 18 using control levers of machine 10 to form a desired topographical feature in the earth. The stored motion is then replayed as the automated tool motion sequence for forming the desired topographical feature at other locations.

The working environment of excavation machine 10 may include uneven terrain. Chassis 12 of excavation machine 10 may be oriented such that the pitch and roll of excavation machine 10 deviates from horizontal and vertical. Pitch and roll measurements are determined by controller 50 by calculating the difference in location of multiple antennas 38 mounted on operator cab 14 or elsewhere on chassis 12. It is also within the scope of the present disclosure that pitch and roll measurements are determined by controller 50 based on feedback from inclinometers or other sensors oriented orthogonally and mounted on operator cab 14 or elsewhere on chassis 12. As a result, controller 50 also determines the pitch and roll of boom arm 22, dipper arm 24, and bucket 20.

Based on feedback from sensors 66 and GPS device(s) 68, controller 50 can determine the position and orientation of arms 22, 24 and bucket 20 relative to chassis 12 as well as the position of excavation tool 18 relative to the targeted area of the ground. Accordingly, controller 50 provides closed loop control of the trajectory and velocity of excavation tool 18 during the excavation.

For further description of exemplary positioning systems and feature location methods and apparatuses, see, for example, U.S. patent application Ser. No. 11/925,075, entitled “Three Dimensional Feature Location from an Excavator,” filed Oct. 26, 2007, and U.S. patent application Ser. No. 13/216,752, entitled “Three Dimensional Feature Location from an Excavator,” filed Aug. 24, 2011, the disclosures of which are hereby expressly incorporated by reference herein in their entirety. Other suitable position detection systems may be provided and implemented with excavation machine 10 such that controller 50 is operative to calculate and implement the tool motion sequence.

As illustrated in FIG. 2, excavation machine 10 includes a display 62, such as a monitor, that is operatively coupled to controller 50 for providing visual feedback to the operator. In one embodiment, display 62 is provided as a simple flat screen display tablet in operator cab 14. In other embodiments, display 62 is a heads-up style display where images are projected or otherwise displayed, for example, on the windows of operator cab 14. Other suitable displays 62 may be provided.

Controller 50 of excavation machine 10 provides a visual representation approximating a map of the job site to display 62 based on stored or received workspace data. The workspace data includes geographic workspace information obtained from drawings or files of the job site that are constructed via measurements taken by hand, by GPS (e.g., GPS device 68), or otherwise. Such geographic workspace information includes information describing the geographical features of the job site, such as the location of above-surface and sub-surface features (e.g., utilities) at the job site. The drawings can be formatted according to any number of known formats, including formats provided with AutoCad™, ESRI™, or other computer aided design tool and mapping formats. Options are provided that allow aerial/satellite maps, such as those obtained from Google Maps or otherwise, to be combined with the workspace data so that a user may correlate map positions with real-world topology of the job site.

Controller 50 receives and integrates information regarding the geographic location of excavation machine 10 and of the desired topographical feature with the workspace data. For example, controller 50 receives the positional information from GPS devices 68 and tool position sensors 66 and the desired geographical location data describing the desired topographical feature. In one embodiment, a user enters the desired geographical location data via an input device 64, such as by drawing the topographical feature on display 62 or by entering the longitude/latitude coordinates. Other suitable means for inputting the desired geographical location data may be provided. Additionally, controller 50 receives and integrates information regarding the geometric dimensions and other desired characteristics of the desired topographical feature with the workspace data.

In an exemplary embodiment, controller 50 outputs the interaction visually onto display 62, as illustrated in FIG. 3. For example, controller 50 displays, in real-time, an image of excavation machine 10 and the desired topographical feature 90 on the map of display 62 at the appropriate geographic location points. The geographic location of excavation machine 10 is combined with the stored workspace data to provide a real-time, interactive representation of the job site in which excavation machine 10 is located. Such mapping informs the user by providing a visual contextual rendering of excavation machine 10 and the desired topographical feature 90 at the job site. Still further, the location of implements, such as boom arm 22, dipper arm 24, and bucket 20 are shown on display 62 in real-time. Exemplary feature 90 of FIG. 3 is illustratively a trench T having a grade line G and a benchmark line B. Additional views of the job site, machine 10, and topographical feature 90 may be provided in addition to the side view of FIG. 3. In one embodiment, the complete record of the geometrical dimensions of desired topographical feature 90 and precise measurements of the desired geographical location of desired topographical feature 90 are recorded in memory 54.

Display 62 of FIG. 3 is illustratively a touchscreen that includes selectable data, illustratively a plurality of buttons 77, 78 and toggle selectors 82, 84. For example, informational button 77 is selected to show a job site (worksite), a workspace, or a side view on display 62. In one embodiment, such as with the side view illustrated in FIG. 3, the position of bucket 20 is shown in real-time relative to chassis 12 of excavation machine 10 during the excavation. Display 62 also depicts the target trench T, which is the exemplary desired topographical feature 90, and identifies the current distance between bucket tip or cutting edge 21 of bucket 20 and the grade line G in field 86 and the current distance between bucket tip 21 and benchmark line B in field 88. Other suitable distances and measurements may be calculated and displayed by controller 50 on display 62. User selection of command or input buttons 78 cause controller 50 to alter the displayed data on display 62 (e.g., pan, zoom, etc.) and perform other various tasks. Command buttons 78 and toggle selectors 82, 84 may be used to describe the desired geometric dimensions and geographical location of the desired topographical feature 90 (e.g., the customized trench or hole) to be formed at the job site. After receiving the appropriate data describing the desired topographical feature 90, controller 50 calculates the required motion of excavation tool 18 and updates the tool motion sequence of code module 58 accordingly. In one embodiment, controller 50 displays the predetermined trajectory of one or more strokes of the tool 18 on display 62 prior to or during the excavation. After digging the custom trench T, the user may use command buttons 78 to cause controller 50 to record the completed trench, the calculated tool motion sequence, and the actual motion of the excavation tool 18 in as-built drawings of memory 54. Display 62 and its corresponding inputs may include other suitable functionality and operation, as described for example in U.S. patent application Ser. No. 13/216,752 referenced herein.

Referring again to FIGS. 1 and 2, excavation machine 10 illustratively includes a control lever or joystick 34 operatively coupled to controller 50. Joystick 34 may alternatively include another suitable operator input device. Joystick 34 is provided in cab 14 and is configured to adjust a velocity and direction (e.g., forward/reverse stroke pattern or sequence) of excavation tool 18 during execution by controller 50 of the tool motion sequence of excavation tool 18. A position sensor 35 (FIG. 2), such as a potentiometer or other suitable sensor, detects the position of joystick 34 and provides a signal representing the detected joystick position/actuation to controller 50. Based on the detected position or actuation of joystick 34, controller 50 controls the velocity or rate of excavation tool 18 during execution of the tool motion sequence. As such, the displacement of joystick 34 is used to specify the instantaneous velocity of the tool tip (e.g., bucket tip 21 of FIG. 1). Accordingly, an operator is able to vary the speed of bucket 20 while controller 50 maintains precise geometry and coordinated motion of the multi-axis excavation tool 18 along the predetermined tool path specified with the tool motion sequence.

Referring to FIG. 4, an exemplary joystick 34 is illustrated. Joystick 34 of FIG. 4 includes a head 40 and a stem 42 pivotally coupled to a joystick base 44. Joystick 34 is configured to pivot relative to base 44 in a forward direction and a reverse direction as represented with line A. Joystick 34 is illustrated in FIG. 4 at its “home” position centered about the z-axis of an x-y-z coordinate system. Forward or reverse movement of joystick 34 along line A in the direction of the y-axis and away from its home position results in controlling increasing the speed of excavation tool 18. In one embodiment, controller 50 controls the velocity of tool 18 to be substantially proportional to a degree of actuation of joystick 34 away from its home position. Further, the order in which excavation tool 18 moves through a series of tool strokes identified with the tool motion sequence is controlled with joystick 34. In particular, movement of joystick 34 in the forward direction away from its home position along the y-axis results in the sequence of strokes being executed in sequential order, and movement of joystick 34 in the opposite, reverse direction away from its home position along the y-axis results in the sequence of strokes being executed in reverse sequential order. As such, based on the position of joystick 34, controller 50 controls both the speed and direction of excavation tool 18 traveling through a sequence of stored, programmed, and/or calculated motion segments. In one embodiment, with joystick 34 at its home position, controller 50 does not move excavation tool 18. As such, an operator may stop movement of tool 18 by returning joystick 34 to its home position. In one embodiment, movement of joystick 34 away from the y-axis (i.e., in either x-axis direction) results in the movement of tool 18 being stopped and/or in the automatic mode being cancelled to revert to manual tool operation.

In one embodiment, the initial movement of joystick 34 away from its home position in either direction results in controller 50 initiating or starting movement of tool 18 along the predetermined path according to the tool motion sequence. In this embodiment, as joystick 34 is moved further from the home position, the corresponding speed of tool 18 is increased by controller 50 proportionally. In another embodiment, upon initiation of the tool motion sequence by a user, such as with an input device 64, controller 50 starts movement of tool 18 along the predetermined path at an initial velocity stored at memory 54. In this embodiment, upon movement of joystick 34 away from its home position, controller 50 adjusts the velocity or rate of tool 18 according to the joystick movement. Other suitable joysticks 34 and joystick configurations may be provided.

In one embodiment, machine 10 includes a second joystick 70 (see FIG. 2) for controlling the mode of operation (e.g., automatic or manual) and/or for stopping operation of tool 18. For example, with joystick 34 being used to control the speed and direction of bucket 20 during the automatic execution of the tool motion sequence, as described herein, an actuation of second joystick 70 is used to cancel or exit the automatic mode and revert the system to manual control. In the illustrated embodiment, the second joystick 70 has the same design as joystick 34 of FIG. 4, although the second joystick 70 may have another suitable design. In one embodiment, joystick 34 is positioned to one side of the operator and second joystick 70 is positioned on the other side of operator such that each hand of the operator may be used to operate a respective joystick 34, 70. A joystick position sensor 71 detects the position of second joystick 70 and provides a signal to controller 50 representative of the detected joystick position.

In one embodiment, second joystick 70 is further used to control the incremental depth of cut for each stroke of tool 18 through the bottom of a trench. Referring to FIG. 4, motion of second joystick 70 along the y-axis is used to advance the depth of cut in either a deeper or shallower incremental step. In this embodiment, motion of second joystick 70 along the x-axis away from the home position results in either halting the tool 18 or reverting the system from the automatic control mode to the manual control mode or both. Another suitable input device may alternatively be used to control the depth of cut of tool 18.

Referring to FIG. 5, a flow diagram 100 of an exemplary method of operation of controller 50 is illustrated for controlling excavation tool 18 to move earth at a job site. While FIG. 5 is described with respect to excavation tool 18 for performing an excavation, the method of FIG. 5 may be implemented for controlling the movement and velocity of any suitable work tool of a work vehicle. Reference is made to FIGS. 1-3 throughout the description of FIG. 2. At block 102, tool control logic 56 controls movement of tool 18 based on a tool motion sequence programmed at controller 50 (e.g., code module 58 of memory 54) to move tool 18 along a predetermined path. As described herein, the predetermined path is calculated by controller 50 such that movement of the tool 18 along the predetermined path is operative to form or dig the desired topographical feature (e.g., trench 90 of FIG. 3) at the job site. The tool motion sequence is calculated by controller 50 to identify the trajectory of one or more strokes of tool 18 based on the desired geometric dimensions and geographical location of the desired topographical feature provided by a user, as described herein. In one embodiment, tool control logic 56 controls tool 18 to move at a predetermined velocity stored at memory 54 or as requested with joystick 34, as described herein.

At block 104, tool control logic 56 detects an actuation of an operator input device, illustratively joystick 34, based on feedback from joystick position sensor 35. At block 106, tool control logic 56 adjusts a velocity or rate of tool 18 during the movement of tool 18 along the predetermined path based on the detected actuation of the operator input device (e.g., joystick 34). For example, prior to the actuation of joystick 34 detected at block 104, controller 50 controls tool 18 to move at a velocity based on the current position of joystick 34, as described herein. Upon detection of further actuation of joystick 34 at block 104, controller 50 adjusts the velocity or rate of movement of tool 18 according to the detected actuation of joystick 34 as tool 18 continues along the predetermined path set forth with the tool motion sequence. In one embodiment, controller 50 controls the velocity of tool 18 to be substantially proportional to the degree of actuation of joystick 34, as described above.

With the tool motion sequence describing a series of strokes or passes of the tool 18 through the earth, controller 50 is further operative to control an order of execution of the sequence of strokes by tool 18 based on the position of joystick 34, as described above. The tool motion sequence describes the stroke trajectory of tool 18, such as the trajectory and orientation of bucket 20, for each stroke of bucket 20 through the earth. In the illustrated embodiment, controller 50 is operative to receive at least one user input identifying at least one of a desired fill percentage of bucket 20, a desired incursion depth of bucket 20, and a desired incursion or approach angle of bucket 20 into the earth. The desired fill percentage identifies the percentage of bucket 20 that is to be filled with material for a given pass or stroke of bucket 20 through the earth. For example, the fill percentage is based on the depth of the cut for the given pass of tool 18. The incursion angle identifies the desired approach angle of bucket 20 relative to the ground (or material) for a given stroke of bucket 20. A user identifies the desired fill percentage and incursion angle of bucket 20 via one or more user input devices 64 (e.g., rotary knob, slide control, inputs 78 of FIG. 3, etc.). Based on these inputs, controller 50 implements the tool motion sequence such that tool 18 has the desired fill percentage and incursion angle for one or more strokes of tool 18 during execution of the tool motion sequence. In one embodiment, the operator may adjust the speed of engine 48 (FIG. 2) to vary the power provided to hydraulic circuit 60 (FIG. 2) for powering excavation tool 18.

In addition to the automated control of excavation tool 18 using the tool motion sequence, an operator may also manually control movement of excavation tool 18 using multiple control levers, as referenced herein. For example, in one embodiment input devices 64 includes control levers or joysticks that are operative to control hydraulic cylinders 26, 28, 30 for manipulating excavation tool 18 without execution by controller 50 of the pre-programmed tool motion sequence in memory 54. For example, each joystick may control one or more hydraulic function of the excavation tool 18 such that manipulation of excavation tool 18 is controlled by controller 50 based on the positions of each joystick and not based on the execution of the tool motion code module 58 stored in memory 54. Input devices 64 of FIG. 2 may be used to control various other systems and devices of excavation machine 10 and excavation tool 18. Exemplary input devices 64 includes foot pedals, a touch screen (e.g., with display 62), a keyboard, a mouse device, other joysticks, selectable buttons, and other suitable input devices.

While this invention has been described as having exemplary designs, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. 

1. A work vehicle for moving earth at a job site, the work vehicle including: a chassis; a ground engaging mechanism configured to support the chassis; a tool movably coupled to the chassis and configured to move earth at the job site; a controller operative to control movement of the tool based on a tool motion sequence programmed at the controller to move the tool along a predetermined path; and an input device movable by an operator and operatively coupled to the controller, the controller being operative to control a velocity of the tool along the predetermined path based on a position of the input device.
 2. The work vehicle of claim 1, wherein the controller controls the velocity of the tool along the predetermined path to be proportional to a degree of actuation of the input device.
 3. The work vehicle of claim 1, wherein the controller controls the movement of the tool along the predetermined path to perform an excavation at the job site.
 4. The work vehicle of claim 3, wherein the tool motion sequence describes a sequence of strokes of the tool through the earth for performing the excavation, and wherein the controller is further operative to control an order of execution of the sequence of strokes by the tool based on the position of the input device.
 5. The work vehicle of claim 1, wherein the controller is operative to calculate the tool motion sequence based on at least one received input identifying at least one of a geometric dimension and a geographical location of a desired topographical feature to be formed at the job site, and wherein the controller controls the movement of the tool based on the tool motion sequence to form the desired topographical feature at the job site.
 6. The work vehicle of claim 5, wherein the tool motion sequence programmed at the controller identifies a stroke trajectory of the tool for each of a plurality of strokes of the tool through the earth.
 7. The work vehicle of claim 5, wherein the at least one received input includes at least one of a depth, a length, a bottom slope, and a width of the desired topographical feature to be formed by the tool.
 8. The work vehicle of claim 5, further including a positioning system in communication with the controller operative to detect a geographical location of the work vehicle, the controller calculating the tool motion sequence further based on the detected geographical location of the work vehicle.
 9. The work vehicle of claim 1, wherein the tool includes a bucket configured to hold material, and wherein the controller is operative to control movement of the tool further based on at least one user input identifying at least one of a desired fill percentage of the bucket and a desired incursion angle of the bucket into the earth during movement of the tool along the predetermined path.
 10. The work vehicle of claim 1, wherein the controller includes at least one processor and a memory accessible by the at least one processor, and wherein the tool motion sequence is identified in a code module stored in the memory of the controller and executed by the at least one processor of the controller.
 11. A method for moving earth at a job site with a work vehicle, the method including: controlling, by tool motion control logic of a controller of the work vehicle, movement of a tool of the work vehicle based on a tool motion sequence programmed at the controller to move the tool along a predetermined path; detecting an actuation of an operator input device, the operator input device being operatively coupled to the controller; and adjusting a velocity of the tool during the movement of the tool based on the detected actuation of the operator input device.
 12. The method of claim 11, wherein the adjusting the velocity includes controlling the velocity of the tool along the predetermined path to be proportional to a degree of actuation of the operator input device.
 13. The method of claim 11, wherein movement of the tool along the predetermined path performs an excavation at the job site, and wherein the tool motion sequence describes a sequence of strokes of the tool through the earth for performing the excavation, the method further including controlling an order of execution of the sequence of strokes by the tool based on a position of the operator input device.
 14. The method of claim 13, wherein the operator input device includes a joystick movable in a first direction and in a second direction opposite the first direction, wherein the sequence of strokes are executed in sequential order based on movement of the joystick in the first direction and the sequence of strokes are executed in reverse sequential order based on movement of the joystick in the second direction.
 15. The method of claim 11, further including: receiving at least one user input identifying at least one of a geometric dimension and a geographical location of a desired topographical feature to be formed at the job site; and calculating the tool motion sequence based on the at least one user input, the controller controlling the movement of the tool based on the tool motion sequence to form the desired topographical feature at the job site.
 16. The method of claim 15, wherein the tool motion sequence identifies a stroke trajectory of the tool for each of a plurality of strokes of the tool through the earth.
 17. The method of claim 16, wherein the tool includes a bucket configured to hold material, the method further including: receiving at least one user input identifying at least one of a desired fill percentage of the bucket and a desired incursion angle of the bucket into the earth for each stroke of the tool, wherein the controlling the movement of the tool is further based on the at least one of the desired fill percentage and the desired incursion angle.
 18. The method of claim 15, wherein the work vehicle includes a positioning system in communication with the controller operative to detect a geographical location of the work vehicle, the calculating the tool motion sequence being further based on the detected geographical location of the work vehicle.
 19. The method of claim 11, further including starting the movement of the tool along the predetermined path based on the tool motion sequence upon detection of a movement of the operator input device.
 20. A work vehicle for moving earth at a job site, the work vehicle including: a chassis; a ground engaging mechanism configured to support the chassis; a tool movably coupled to the chassis and configured to move earth at the job site; a controller programmed to move the tool from a first position to a second position along a predetermined path; and an operator input device in communication with the controller to adjust a rate at which the tool moves from the first position to the second position.
 21. The work vehicle of claim 20, wherein the controller controls the rate at which the tool moves from the first position to the second position to be proportional to a degree of actuation of the operator input device.
 22. The work vehicle of claim 20, wherein the controller is operative to calculate the predetermined path based on at least one received input identifying at least one of a geometric dimension and a geographical location of a desired topographical feature to be formed at the job site, and wherein the controller is operative to move the tool along the predetermined path to form the desired topographical feature at the job site.
 23. The work vehicle of claim 22, wherein a tool motion sequence programmed at the controller identifies the predetermined path, and wherein the tool motion sequence identifies a stroke trajectory of the tool for each of a plurality of strokes of the tool through the earth to identify the predetermined path.
 24. The work vehicle of claim 20, wherein the tool includes an excavation bucket configured to hold material, and wherein the controller calculates the predetermined path based on at least one user input identifying at least one of a desired fill percentage of the excavation bucket and a desired incursion angle of the excavation bucket into the earth.
 25. The work vehicle of claim 20, wherein the controller is programmed to initiate movement of the tool from the first position to the second position upon detection by the controller of a movement of the operator input device. 